Slackel is running on Sourceforge.net. I received a message that they drop the php 5.4 and i have to upgrade the site to run under php 7.4
I upgraded the phpbb 3.1.9 to latest phpbb 3.3.10 to run under php 7.4
The phpbb 3.3.10 can run under php 8 which will happen on Sourceforge in near future.
Everything went fine and site is up and running.
Here can see the php version on Sourceforge.